RedBook audio, which is the kind of audio a CD plays in a Hifi CD drive, can be played in two ways (on a PC):

- via a digital or analogue output on the CD drive itself, directly to a sound card, which can mix that sound in with other audio and output it via the normal output.
- via digital audio extraction (DAE), which reads the same audio data but makes it available via the IDE bus, and may be utilized via a driver, the application, or some combination of both.

Most DOS games will rely on the former, DAE may be supported under windows by some applications.

However most games switched to using PCM audio, which are audio data stored as regular files on the CD filesystem - not as RedBook structured data, so DAE was no longer necessary.

If you have dual sound cards, and you use one for DOS, and one for Windows, you may not have a problem for the above reasons. Your windows games may not depend on RedBook audio on the CD (or may utilize DAE), so you can just output the CD to the DOS soundcard for those games that require it.

You might be able to do something trick like outputting one sound-card into the other to mix RedBook audio output captured by one card with the other card that is playing sound effects.

You might be able to output analogue RedBook to one sound-card and digital to the other, depending on the outputs your CD drive has, and the input the sound cards have respectively.

ALSO - the IDE connector on your sound-card is NOT a "audio connector" - it is just an IDE connector (mostly), and the sound-card reserves the normal DMA ports so that the CD is seen as it's own device. You would still need to connect the RedBook audio out into the sound-card even in that case.

Your questions are complicated and give me a heachache, but the above might give you a bit of food for thought.

Thank you for the ideas sir, I think I almost figured it out 😁

I actually have some REALLY stubborn Windows games that refuse to play CD audio digitally - to the extent that I even wanted to _inmm them all (patch them that they would read CD tracks from HDD) - that is why I'm in such an awkward dilemma.

Seems like using the line-out function wisely would save my day. ;D

The only remaining problem being: will the PCI card actually play CD audio when it's not initialized under DOS?

Just get a second CD drive, and connect each drive to a different card. This way you have all bases covered.

tenyuhuang wrote:

The only remaining problem being: will the PCI card actually play CD audio when it's not initialized under DOS?

Under DOS a PCI sound card will not even been seen without initialization. Some ISA cards won't work without initialization. I don't think there is any special need for a driver to make use of CD audio, but if you can't see the card it doesn't even matter.

dr_st wrote:

Just get a second CD drive, and connect each drive to a different card. This way you have all bases covered.

I'd of course love to do that, but I'll have to get myself another case: I just don't have enough front slots 😁

squiggly wrote:

tenyuhuang wrote:

The only remaining problem being: will the PCI card actually play CD audio when it's not initialized under DOS?

Under DOS a PCI sound card will not even been seen without initialization. Some ISA cards won't work without initialization. I don't think there is any special need for a driver to make use of CD audio, but if you can't see the card it doesn't even matter.

Found myself some time to test some speculations out. Turns out that as long as the CD drive is visible under DOS, it doesn't matter if the sound card is initialized; however, without initialization, you could only get CD Audio from the drive's front panel (of course), as opposed to line out on the rear.

That being said, I might wanna to connect the front panel to another card's line in, which is the imperfect but the simplest solution so far. 😊